CVE-2026-53281
Published: July 1, 2026Last modified: July 1, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Avoid NULL pointer dereference or refcount corruption Commit 60f030f7418d ("iommu/vt-d: Avoid use of NULL after WARN_ON_ONCE") fixed a NULL pointer dereference in an unlikely situation partly. If dev_pasid is not found in the dev_pasids list, it remains NULL. However, the teardown operations are executed unconditionally, this lead to a NULL pointer dereference or refcount corruption. If the domain was never attached to this IOMMU, info will be NULL, which would cause an immediate dereference when checking --info->refcnt. Even if info is not NULL, decrementing the refcount without having removed a valid PASID might unbalance the count. This could lead to premature dropping of the refcount to 0, potentially causing a use-after-free for the remaining active devices sharing the domain. Fix it by returning early if dev_pasid is NULL, before executing the teardown operations. Issue found by AI review and suggested by Kevin Tian. https://sashiko.dev/#/patchset/20260421031347.1408890-1-zhenzhong.duan%40intel.com
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 8.8 |
| Attack Vector | LOCAL |
| Attack complexity | LOW |
| Privileges required | LOW |
| User interaction | NONE |
| Scope | CHANGED |
| Confidentiality | HIGH |
| Integrity impact | HIGH |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | linux-lts | Not affected (6.1.33-r0) |
| 25 LTS | linux-lts | Vulnerable (6.12.92-r0) | |
| Stream | linux-lts | Fixed (6.18.35-r1) |
References
- https://access.redhat.com/security/cve/CVE-2026-53281
- https://bugzilla.redhat.com/show_bug.cgi?id=2493728
- https://git.kernel.org/stable/c/79ea2feb917b05366b49d85573c9c5331f043b2c
- https://git.kernel.org/stable/c/9022cb9ac0c2a72a57fa8ebf92ac74f953ca0153
- https://git.kernel.org/stable/c/cdfe3c9f2c9e28a8651ee463c88ad191ced2f840
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53281.json